RICHMOND — One Republican delegate warns that Virginia is splitting in two. Another would support returning liberal Arlington and Alexandria to the District of Columbia. Lawmakers in West Virginia have offered to annex rural Frederick County, outside Winchester, to liberate it from its rapidly urbanizing home.

The change that Democrats promised in last fall’s election campaigns is hitting Richmond with full force, casting new light on political and cultural divisions that have simmered for years. As leaders quickly advance gun control, women’s rights and LGBTQ protections, many Republicans charge that they’re trampling on the interests of a new minority: rural conservatives who long held sway in the Capitol.

“We don’t need one part of Virginia pitted against another just because of a political agenda,” House Minority Leader Todd Gilbert (R-Shenandoah) said.

Last week’s massive gun rights rally was the rawest reaction yet to the demographic shifts turning Virginia from red to blue. While the state’s electorate has been tilting Democratic for more than a decade, this year’s General Assembly session shows what consolidated power looks like, with blue majorities in the legislature joining forces with Democratic Gov. Ralph Northam.

The abrupt change is playing out in ways large and small. Democrats grabbed national attention for approving the Equal Rights Amendment, while also changing the pronouns in official House rules from “he/him” to “she/her.” The weekly “Speaker’s Bible study” has become an “interfaith devotional” that kicked off with a rabbi. The word “Militia” is gone from the name of the House Public Safety Committee.

Democrats say the changes are meant to be more inclusive. “We’re telling people, ‘Yes, you belong here, you have someone you can relate to here,’ ” said Del. Danica A. Roem (D-Prince William), Virginia’s first openly transgender state lawmaker.

Women and minorities have vaulted into historic positions of power. Beyond the first female Speaker and House majority leader, African Americans chair seven of the 14 standing House committees, including the powerful Appropriations Committee that controls state purse strings.

Regionally, the shift is equally striking. In both the House and Senate, Democrats from the D.C. suburbs control the majority of committee chairmanships; under Republicans, the powerful jobs were distributed to lawmakers from all over the state, with a tilt toward rural areas.

The upshot is that white men from red parts of Virginia hold less power this year than any time since Reconstruction.

In a sense, the change addresses old imbalances — and not just racial ones. Northern Virginia has never had positions of influence equal to its proportion of the state’s population and wealth, particularly in the House of Delegates. And Republicans over the past quarter-century have used their majorities to pass measures that Democrats found extreme, such as requiring ultrasounds before abortions or undoing any hint of restrictions on guns.

Northam’s predecessor, Terry McAuliffe (D), vetoed more bills than any governor in state history in what he called a “brick wall” against the excesses of a Republican-controlled legislature.

The Senate, which has flipped control more often than the House, has made the transition fairly smoothly — though Republicans complained that no members from the mountainous southwest are part of the powerful Finance Committee.

In the House, which was under GOP control for 20 years, the shift has been painful. Former House speaker Kirk Cox (R-Colonial Heights) opted not to take over as minority leader and sits quietly during floor sessions, grimacing and whispering with colleagues.

Del. Robert D. Orrock Sr. (R-Caroline), the GOP’s master of parliamentary rules, routinely bounces to his feet to challenge Speaker Eileen Filler-Corn (D-Fairfax) on what he says are procedural errors. Gilbert, the minority leader, lectured the new leadership in an extraordinary speech Jan. 17.

“I realize this is a jubilant time for Democrats,” Gilbert said, while warning of “growing concern about how we are functioning as an institution.” The pace of taking up bills was too slow, he said, pointing out that the session would be 14 days old before the first measures were likely to pass out of the House.

Committees have canceled meetings, he noted, and legislative aides complained of low morale. The session “seems slow, it seems awkward and it doesn’t seem like it is getting any better,” he said.

Filler-Corn responded with a frosty promise that work will be done on time. And Del. Luke E. Torian (D-Prince William), the first African American to chair the Appropriations Committee, angrily instructed Gilbert not to “single us out as though we are lazy.”

Privately, many Democrats said they bristled at the optics of Gilbert, a white man, seeming to question the competence of female and black leaders.

The phenomenon repeated Monday when Gilbert led an attack on a bill loosening abortion restrictions as a large crowd of women waited in the House gallery to witness final passage of the ERA. Lobbing repeated questions at House Majority Leader Charniele L. Herring (D-Alexandria), the bill’s sponsor, Gilbert at one point suggested she had missed something because she was consulting a colleague.

“I am standing here on my own,” Herring shot back. Filler-Corn soon cut off debate. The abortion rights bill advanced, and then the House approved the ERA bill.

Some Republicans say Democrats are abusing their new power.

“When you feel like one side dictates all the terms, I do think it exacerbates . . . differences in ways that are unhealthy,” said Del. Nicholas J. Freitas (R-Culpeper).

“I really think it’s going to just build in the weeks ahead as we see pretty dramatic policy shifts in areas that relate to business, taxation . . . abortion [and] other things,” said Del. David A. LaRock (R-Loudoun).

Earlier this month, with one eye on history and the other on the gun rights movement sweeping across Virginia, Republicans in the West Virginia legislature advanced a resolution inviting neighboring Frederick County to cross the border and join the mountain state. Such an offer had technically been on the table since the Civil War, when West Virginia broke away from Richmond rather than secede.

“West Virginia has a very strong tradition of being jealous and guarding individual liberties, including those that are protected by the Second Amendment,” West Virginia state Sen. Charles S. Trump IV, who sponsored the resolution, said in an interview.

While no one in Richmond seems keen on the idea, the proposal got LaRock thinking about how part of modern-day Alexandria and Arlington were originally included in the District of Columbia, until changing laws on slavery caused them to leave in the 1840s.

Maybe, he told a local newspaper, they should go back.

There are “dramatically different values” in Arlington and Alexandria than other parts of Virginia, LaRock said in an interview with The Washington Post. While the idea initially was just to illustrate “general dissatisfaction” with changes in Richmond, LaRock said he’s half-serious about it.

“If I saw a proposal that was widely accepted by many, many others and was the most peaceful way to reconcile some of the situations now that are kind of beginning to build, I would entertain that possibility,” he said.

But the problem for Republicans is that the values LaRock sees in Arlington and Alexandria have spread throughout the state. In last fall’s elections, it was suburban districts in places such as Prince William County, Chesterfield County outside Richmond and parts of Hampton Roads that gave Democrats their majorities in the legislature.

“This is them realizing and being disappointed that they didn’t get more votes than they did,” Del. Jerrauld C. “Jay” Jones (D-Norfolk) said. “We are executing the will of the people of Virginia who came out to the ballot box.”

Northam, who has become the focus of rage from pro-gun activists for his promise of gun control, said through a spokeswoman that his agenda is more in step with the values of people across the state.

“Virginians have long supported things like universal background checks, ending the attacks on women’s rights, and ensuring workers can support themselves and their families,” the governor said in a written statement. “The difference is now, our legislature is finally listening.”

It’s ironic that Northam — who hails from the Eastern Shore and used to vote for Republicans — has become the bane of conservatives. When he ran for governor in 2017, some Democrats worried his rural roots and country accent would alienate suburban voters.

The day after the Richmond gun rally, Northam appeared in Franklin County in far Southwest Virginia — a place that has declared itself a Second Amendment sanctuary — to tout a business that was expanding. The next day, he announced a series of grants to expand rural broadband.

But his agenda for the coming weeks of the session is unabashedly blue. Even before Democrats have finished approving gun-control bills, they will move on to measures that expand voter access and ban discrimination against LGBTQ people. Democrats in the legislature also hope to raise the minimum wage, decriminalize marijuana, eliminate cash bail and more.

Roem, who in only her second term is now the first openly transgender person to chair a subcommittee, said Republicans need to get over it.

“Keep in mind that those of us from Northern Virginia had to very much live with a state that was run in large part by people from places outside of Northern Virginia for a long time,” she said.

Now that the state’s most populous and wealthy region is in charge, she said, the message isn’t separation; it’s inclusion.

“We’re just reflective of where we are as a commonwealth,” Roem said. “That doesn’t change the fact that we have different parties, different regions, different values. . . . Everyone just needs to learn how to coexist.”

An earlier version of this article misstated how long the House of Delegates had been under Republican control before Democrats came to power this year. It was 20 years, not 24 years.